what compression will i have? seems like it will be easier to get some 243 rather than spend the money getting the 317s worked. or am i wrong? i searched and it said 243s outflow 317 stock for stock.

 

pm wheatley. he has a lq4 with .030 milled 243s. i think his around 10.5-10.7ish. I THINK.

 

The 243s flow like 3-4 cfm more up top, it's negligible. Just mill your 317s .040" and you will be at 10.6:1

 

My 243 heads are milled .035 59cc,this brought my compression up to about a 10.7:1-10.8:1
the 243 heads flow just a hair better but not much over the 317 heads.
Mine are not ported yet,but that is about to change

 

Are you sure that's right charlie? I thought LQ4 with 64cc's is right at 10.6:1

 

It should be right.This is what Robert at MTI said when I had them done and also several others.

 

What thickness head gasket, is that with? I have an LQ4 with .020" of my 243's and a .040" cometics and I'm real close to 11-1...

 

Stock head gaskets!!

 

i machined my own 243 and gt thm flowing 283cfm peak on 4.03 bore.
no actual metal cut out besides the valve throat area and what the cartridge removed. with 2.02 valves, 4angle vj and backcut on valve. milled .030
they support around 493rw in replacement .060 over lq4 piston. is at around 11.28:1 with .035 quench

 

idk how much compression but i know for a fact thats a great motor combo, thats what i will be doing hopefully by the summer or earlier